Many gym rats face the question of whether to hit the treadmill first or go straight for the weights. Our answer?

Activities like running, cycling, rowing, and so on, rely heavily on your body’s carbohydrate stores (the more intensely you train, the greater your need for carbohydrates as a fuel source). Those stores may be at least partially depleted by the time you begin the lifting portion of your workout. And weight lifting is entirely dependent on carbohydrates as a fuel source. Though your body burns fat between sets, it relies on carbohydrate energy during sets. If you’ve already depleted your carb supply via aerobics, you’ve compromised your lifting performance.